Ewan Keith focused on stabilizing incremental operations in the databricks/dbt-databricks repository by addressing schema drift related to foreign key constraints. He implemented a solution in Python and SQL that ensures multiple foreign key constraints persist as configuration changes during incremental runs, thereby improving data integrity and reducing unnecessary full-refresh triggers in production pipelines. Ewan enhanced both unit and integration test coverage to validate the persistence of these constraints and updated documentation to reflect the changes. His work demonstrated depth in data modeling and database management, delivering a robust fix that supports reliable incremental behavior across diverse deployment environments.